HGG Community Forums

Short answer: mosaic means brindle. It's not actually a genetic trait so no you can't (really) breed for it. Brindle parents are slightly more likely to produce Brindle foals, but it's still unlikely

The long answer, now that I'm home from work, is that in real life brindle horses are chimeras (the genetics kind, not the mythology kind). A chimera, in this sense, is an individual that has two completely separate genomes because two separate embryos (fraternal twins) fused early in development. Chimerism can have all sorts of interesting effects, including essentially two sets of coat color arranged in stripes, ie brindle.

In real life I don't know whether it's any more likely for brindles to pop up from lines with a history of brindle than from lines without, but it does seem to be more likely in the game. It would make sense to me if it was, as brindle is basically fused twins, so lines with a tendency to produce twins could hypothetically have a higher likelihood of brindle as well. But I don't know.

There is an inheritable 'brindle' in real life, but it's actually a disorder with several negative effects, so it's not worth the cool look.

A mosaic is actually something a little different, and I think in horses brindles tend to come from chimerism, not mosaicism, but the point is that's what it's referring to when you see that at the end of a horse's genome in the game.

So, it means the horse is brindle, and you can't really breed for it, though many of us have tried with rare exciting moments of success. I actually got a second gen brindle colt from two brindle parents this season, and when he grows up I'm gonna cross him with somebody else's second gen brindle filly! I will probably fall out of my chair if they actually produce a brindle foal, but they're a good cross anyway, so I'm going for it